Audio Woes

[Reiketsukan]

When I first got my Supra this spring, one of the first things I noticed was that only half the spears worked. So, as soon as I could afford it, I replaced the archaic, malfunctioning stock head unit with a nice Sony deck. It sounds great, but now I have a new problem.

When I turn up the volume past a certain point, the speakers stop for a second, then go back on and repeat this until I turn it down a bit. I know It's not my speakers because they're all brand new Infinity's, and I'm guessing it's not the deck because the faceplate stays fully illuminated and operable when this happens. My guess is that it's caused by my stock amp.

Could this be caused by my stock amp getting an already amplified signal from my aftermarket deck? It puts out 50w and I believe the stock head unit wasn't amplified at all. Is it possible to eliminate my stock amp by just matching the input wires to the output wires?

I took a look under my passenger seat and it looks like I could just match the colors.
I'm pretty skilled at soldering and could make it nice and clean, but I'd like a little feedback before
I give it a shot. Has anyone else had this problem?
Thanks in advance!

 

[BoostJunkie]

make sure your connections on the speakers are not touching metal. The Sony headunit is only pushing 15 watts RMS. Could be a possibility of the stock amp goin bad.

 

[Reiketsukan]

make sure your connections on the speakers are not touching metal. The Sony headunit is only pushing 15 watts RMS. Could be a possibility of the stock amp goin bad.

When I installed the new speakers, I snipped the wires going to the old ones very close to the terminals so I could solder them onto the new speakers and reuse the stock plugs, making them kinda 'plug-n-play' and ensuring that there was no risk of any of the connections touching metal.

The box my Sony head unit came in said 50 watts, but when it comes to 'Peak' and 'RMS' and all that jazz... I get a bit lost with the terminology. Not saying you're wrong at all! Any votes for snipping those two wire harnesses a couple inches back from the plugs and matching up the colors? Any other info / advice would be appreciated!

 

[BoostJunkie]

Max is 50 x 4. RMS is 15 x 4. Just about all radios are the same power. RMS( Continuous) is the one you want to focus on.

Yeah you could cut the harnesses and splice them together, just not sure if it is color matched between the two, but you can bypass the amp.

 

[Reiketsukan]

Max is 50 x 4. RMS is 15 x 4. Just about all radios are the same power. RMS( Continuous) is the one you want to focus on.

Yeah you could cut the harnesses and splice them together, just not sure if it is color matched between the two, but you can bypass the amp.

That makes sense. Thanks for clearing that up for me! I'm going to give that a try tomorrow if I get time. Any more input is welcome!

 

[Reiketsukan]

That makes sense. Thanks for clearing that up for me! I'm going to give that a try tomorrow if I get time. Any more input is welcome!

I snipped off the 2 plugs going into the stock amp and matched up all the colors... nothing happened! My deck wouldn't turn on! So I re-soldered the plugs back on. It works again like it did before, clipping out at high volume.

I really have no idea why this didn't work... Is there a proven way to eliminate the stock amp? Is there a possibility that my new deck/speakers aren't getting enough power? The speakers clip when bass hits hard when the volume is up, or if it's loud enough without bass, so I could see where it might be a possibility. Any ideas or input will be greatly appreciated!!

 

[romaniello]

It only costs about $40 to have a proper shop fix this for you.

 

[BoostJunkie]

The colors on the two plugs probably wont be the same. Get the wire diagram from the TSRM and then try it.

 

[Reiketsukan]

The colors on the two plugs probably wont be the same. Get the wire diagram from the TSRM and then try it.

I might not be reading this right, but I don't think it details what wires got to what as far as the stock amp is concerned... Did I pull up the right diagram?

 

[BoostJunkie]

From the amp it tells you what wires are to what speaker. Pull the radio back out and see what wires are for the speaker wires.

 

[Reiketsukan]

It only costs about $40 to have a proper shop fix this for you.

I should have thought of that... A good friend of mine spent 2 years in the mobile install bay at a local Best Buy. I gave him a call and he said that he'd seen new decks cause this to stock amps before and that he'd bypass the amp for me this weekend. Thanks for the help, BoostJunkie and romaniello!

 

[Pernilongo]

So right now you have a head unit that suppose to sent high level signal directly to speakers go to another amp? and then this second amp sends another high level signal to speakers?

 

[91TurboDave]

Bypass only the speaker terminal wires at your stock amp! I de-pinned the connector on the stock amp output and soldered that to my 9-wire bundle that feeds the signals to my Mids/Highs amp. RCA's from deck to amp-The setup works great...The signal clipping is a thermal protection of the stock amp. As you increase the wattage entering the amp, the signals leaving are amplified past the ability of that units design, heat and over peak signal causes the amp to protect itself, hence clipping until the signal returns to a useable level (turning down the volume)
The stock deck is running about 17(? correct me if I am wrong) watts peak (that is where the stock amp comes into play) anything over that peak voltage is taxing your stock amp. Just de-pin the imput, run to amp, run the amplified signal back to the amps location, de-pin the output side, and connect amplified signal to depinned output connector wires..and viola stock amp bypassed!, leave all other wires in place to the stock amp except the imput/output....the amp also controls your power ant, your radio power, and the stock noise filter.

Hope this helps

 

[Reiketsukan]

Bypass only the speaker terminal wires at your stock amp! I de-pinned the connector on the stock amp output and soldered that to my 9-wire bundle that feeds the signals to my Mids/Highs amp. RCA's from deck to amp-The setup works great...The signal clipping is a thermal protection of the stock amp. As you increase the wattage entering the amp, the signals leaving are amplified past the ability of that units design, heat and over peak signal causes the amp to protect itself, hence clipping until the signal returns to a useable level (turning down the volume)
The stock deck is running about 17(? correct me if I am wrong) watts peak (that is where the stock amp comes into play) anything over that peak voltage is taxing your stock amp. Just de-pin the imput, run to amp, run the amplified signal back to the amps location, de-pin the output side, and connect amplified signal to depinned output connector wires..and viola stock amp bypassed!, leave all other wires in place to the stock amp except the imput/output....the amp also controls your power ant, your radio power, and the stock noise filter.

Hope this helps

I'm glad someone has had the same problem! Could you do me a favor and tell me which colors to do what with? I'm not sure which plug is input or output. And... you kinda lost me a bit there. Please reference to the pic in my first post. Thanks a ton!!!!

 

[3p141592654]

Hold on a second. If you want to delete the stock amp, then disconnect the amp harness where it connects to the dash harness in the center console. It connects to the standard 10pin/6pin Toyota radio connectors there leaving you with the standard interface that you can connect to with any Toyota 10p/6p adapter.

The under seat power amp was an option so internally amplified radios are a direct fit to the stock wiring.

 

[Reiketsukan]

Hold on a second. If you want to delete the stock amp, then disconnect the amp harness where it connects to the dash harness in the center console. It connects to the standard 10pin/6pin Toyota radio connectors there leaving you with the standard interface that you can connect to with any Toyota 10p/6p adapter.

The under seat power amp was an option so internally amplified radios are a direct fit to the stock wiring.

Could it really be that easy? Would I find this tucked behind the deck? I'm going to check this out today before my buddy comes over to bypass it for me.

 

[91TurboDave]

I could be wrong, it has happened...but I don't think so, well not on my car anyway.
Before I installed my system I researched any adapter I could to try and do an aftermarket direct fit deck install, there was not one to be had. There is NO secondary path to the speakers that IS NOT amplified(On option supras with the amplified system, which I think is all of them:biglaugh. The supras that were NOT equipped with amplifiers had a similar looking harness but it was/is completely different. If the stock system has an amplifier, it MUST be bypassed there is NO other path to get the signals to the speakers. Simple layout...Stock deck(low level signal output)==>Stock amplifier(amplified high:runaway:level signal)==>Speakers. If you send an aftermarket decks amplified signal to a stock supra amplifier you will get clipping at high levels and will be doing damage to the amplification circuit. That amplifier was designed to work with the stock deck, change the deck you must bypass the amp, or eventually you will blow it... Or try it another way and have to replace more stuff later...your choice.

just my 2cents

 

[91TurboDave]

I could be wrong, it has happened...but I don't think so, well not on my car anyway.
Before I installed my system I researched any adapter I could to try and do an aftermarket direct fit deck install, there was not one to be had. There is NO secondary path to the speakers that IS NOT amplified(On option supras with the amplified system, which I think is all of them:biglaugh. The supras that were NOT equipped with amplifiers had a similar looking harness but it was/is completely different. If the stock system has an amplifier, it MUST be bypassed there is NO other path to get the signals to the speakers. Simple layout...Stock deck(low level signal output)==>Stock amplifier(amplified high:runaway:level signal)==>Speakers. If you send an aftermarket decks amplified signal to a stock supra amplifier you will get clipping at high levels and will be doing damage to the amplification circuit. That amplifier was designed to work with the stock deck, change the deck you must bypass the amp, or eventually you will blow it... Or try it another way and have to replace more stuff later...your choice.

just my 2cents

I looked again at my diagrams and on my model(91turbo) there just isn't another path to the speakers...I am not completely familiar with all of the model differences...what year supra do you have? should have asked this first. I don't believe it is just as simple as that...I could not find the pigtail to which he was referring, but it would have to be a complete alternate path for the power ant., noise filter, speaker signal wires, and radio power/ground.
If such an alternate harness exists and I missed it I will feel like a dumbass because that was a ton of work I could have saved myself during install.
Don't want you cutting wires you don't have to.

 

[supraman7mgte]

I'd just ditch the stock amp altogether and run fresh wiring to all components.
I had to tear out alot of my interior just to do it,but none of it gave me any problems.

 

[3p141592654]

Well, you didn't look very hard then. Here is the amp harness. You will note that it plugs into the standard 10p/6p connectors along with the antenna connectors, loops under the carpet to the amp, then back to the console with the funny 14 or 15pin amp connector to the head unit.

Unplug that harness and you have direct access to the 4 speaker channels through the dash 6p/10p connectors.

http://www.cygnusx1.net/Supra/Library/EPC/291420/catalog.aspx?F=8601&P=2